Field of the Invention
The present invention relates to the field of flexible tubes, and more specifically to the heads of such tubes.
Description of the Related Art
Flexible tubes commonly consist of a tube head associated with a skirt, the tube head comprising a neck for removing a product contained in the tube, while the skirt forms the internal volume of the tube which is designed to receive a product.
The skirt is conventionally formed from a multi-layered sheet which is designed to have satisfactory mechanical resistance and sealing properties.
The tube head is, however, commonly produced by plastics injection, and this may prove to be unsatisfactory for certain applications owing to the very aggressive nature of some products.
To solve this problem, a plurality of solutions have been proposed, particularly including a metal insert which fits to the inner face of the shoulder of the tube head so as to form a barrier which separates the tube head itself from the product contained in the tube and thus protects said tube head.
U.S. Pat. No. 3,260,411 to Egremont can be cited in particular and includes a flexible tube structure of this type comprising an insert which is arranged in the tube head and is shaped so as to fit to the profile of the shoulder of the tube head.
However, tube head structures of this type are complex and expensive to produce, the barrier properties of the insert are diminished owing to the significant plastic deformation to which it is subjected, and the prolonged periods of storage of the product may therefore lead to the tube head being broken down by the product.